SeChat - AES encrypted chat written in Java

This is a Java implementation of the Advanced Encryption Standard (AES) using Cipher feedback (CFB) mode of operation for encrypting/decrypting a chat using sockets. SeChat can be used in two ways:

• To chat with another person by connecting to another computer running SeChat. To do this, you will need to run SeChat directly on your computer by either downloading the source code and compiling it, or by downloading the SeChat.jar file and double clicking it. Simply enter a name, the Host IP of the computer running an instance of SeChat, the key (can be anything since it is SHA-256 hashed), the key length, and then click Connect. The applet version cannot be used for this purpose as the applet needs to be signed to allow socket connections.
• When SeChat is not connected for chatting, it can be used to encrypt text, such as e-mail. The output when SeChat is given in Hexadecimal, which can then be sent over email and decrypted by the recipient. The applet version can be used for this purpose.

To encrypt text or an email, simply type a key (which is then SHA-256 hashed, so the key can be a string of any length). Then enter your plain text on the lower text box, and click Encrypt. The output is given as Hexadecimal text which can be copied and sent through email.

To decrypt, copy all the encrypted Hexademial text and paste it in the lower box. Then enter the same key used for encryption and click Decrypt. The plain text is then shown on the upper text box.